https://doc.rust-lang.org/rust-by-example/scope/lifetime/sta... says:
> As a reference lifetime 'static indicates that the data pointed to by the reference lives for the remaining lifetime of the running program.
> As a reference lifetime 'static indicates that the data pointed to by the reference lives for the remaining lifetime of the running program.
I don't know if `unbounded` would immediately be understood by someone new to Rust, but it captures that `T: 'static` is a negating assertion. I.e. it largely says what it can't be.